What We Study

NIEHS intramural scientists have defined descriptive terms of particular relevance to their own research, and have ranked those terms accordingly. This search feature obtains best-matches with the terms you choose, and shows an overall score based on the scientific rankings.

Research

NIEHS research uses state-of-the-art science and technology to investigate the interplay between environmental exposures, human biology, genetics, and common diseases to help prevent disease and improve human health.

Research Highlights

The vision of the NIEHS is to use environmental health sciences to understand human disease and improve human health. Use the search box to see research highlights from NIEHS scientists since its founding in 1966.

Technology Transfer

Visiting NIEHS

About NIEHS

The National Institute of Environmental Health Sciences (NIEHS) is expanding and accelerating its contributions to scientific knowledge of human health and the environment, and to the health and well-being of people everywhere.

Research, funded in part by NIEHS, has uncovered new details about the regulation of telomeres. These repeated DNA sequences protectively cap the ends of chromosomes and play an important role in cancer and aging.

Telomeres become shorter every time a cell divides. Once they are too short, telomeres send a signal for the cell to stop dividing permanently, which weakens the ability of tissues to regenerate and plays a role in many aging-related diseases. In contrast, most cancer cells show elevated levels of the telomere-lengthening enzyme telomerase, allowing cancer cells to divide indefinitely.

To better understand what happens to telomeres damaged by oxidative stress, the researchers examined 8-oxo-7,8-dihydro-2'-deoxyguanine (8-oxoG), a common DNA lesion caused by oxidative stress. The research revealed that when a nucleotide containing 8-oxoG was incorporated into a telomere, any further elongation stopped. By contrast, 8-oxoG lesions found within the telomeric DNA promoted telomerase activity and telomere elongation. These findings showed the mechanism by which the 8-oxoG lesion arises in telomeres dictates whether telomerase is inhibited or stimulated and thus determines whether the telomere is shortened or lengthened.

The new information revealed by this study could be useful for developing new ways to fight cancer and therapies that could help lessen the effects of aging.